Alzheimer's disease is linked with the accumulation of two distinct brain lesions, beta-amyloid plaques with amyloid beta-peptide (Aβ42) and neurofibrillary tangles (tau-peptides). Both plaques and tangles accumulate in specific brain regions critical to learning and memory. This region is called the hippocampus and in Alzheimer's disease it becomes one of the first regions of the brain to suffer attack. Memory problems and disorientation are among the first symptoms of Alzheimer's disease.
Neuroscientists believe that the accumulation of amyloid plaques is the initiating trigger of Alzheimer's disease. It is believed that the progression of the disease can be stopped by early treatment of the plaques. New findings from animal trials strongly support this theory.
By administering anti-beta amyloid antibodies directly into the hippocampus, the antibodies can clear the amyloid plaques within days. This is followed some days later by the clearance of the neurofibrillary tangles.
Former human studies were terminated due to severe side effects (meningoencephalitis) of administering fragments of the amyloid protein to vaccinate patients. It is believed that the direct infusion of anti-beta amyloid antibodies will overcome this limitation.
Methods of administering a drug or other material to a target part of the body are known in the art. For example, U.S. Pat. No. 6,026,316 discloses a method for targeted drug delivery into a living patient using magnetic resonance (MR) imaging. The method uses MR imaging to track the location of drug delivery and estimate the rate of drug delivery. More particularly, an MR-visible drug delivery device is positioned at a target site to deliver a diagnostic or therapeutic drug solution into the tissue. The spatial distribution kinetics of the injected or infused drug agent are monitored quantitatively and non-invasively using water proton directional diffusion MR imaging to establish the efficacy of drug delivery at a targeted location.
U.S. Pat. No. 5,720,720 discloses a method of high-flow microinfusion that provides convection-enhanced delivery of agents into the brain and other solid tissue structures. The method involves positioning the tip of an infusion catheter within a tissue structure, and supplying an agent through the catheter while maintaining a pressure gradient from the tip of the catheter during infusion. The method can be used to deliver various drugs, protein toxins, antibodies for treatment or imaging, proteins in enzyme replacement therapy, growth factors in the treatment of various neurodegenerative disorders and viruses and gene therapy.
U.S. Pat. No. 5,735,814 discloses techniques for infusing drugs into the brain to treat neurodegenerative disorders by an implantable pump and catheter. The drugs are capable of altering the level of excitation of neurons in the brain. A sensor is used to detect an attribute of the nervous system which reflects the hyperexcitation of the nerve cells projecting onto the degenerating nerve cells, and a microprocessor algorithm analyzes the output from the sensor in order to regulate the amount of drug delivered to the brain.
Finally, U.S. Pat. No. 6,549,803 discloses the movement of material in an organism, such as a drug injected into a brain. The movement is modeled by a uniformly structured field of static constants governing transport by moving fluid and diffusion within the fluid. This supports planning of material introduction, (e.g., infusion, perfusion, retroperfusion, injections, etc.) to achieve a desired distribution of the material, continuing real-time feedback as to whether imaged material is moving as planned and will be distributed as desired, and real-time plan modification to improve results.